Effects of parental alienation include low self-esteem and self-hatred

Why is the World Health Organisation only just now talking about including it into the ICD11? Is this because it is a new area of research?

Parental alienation is a relatively new coined concept which has emerged in research in the 1980s.

Although the existence of parental alienation has probably always existed, it could have easily been termed under other mental and behavioural issues. Furthermore, given that the numbers of separations and divorce are on the increase locally, the incidence of parental alienation might be more observed and visible.

The inclusion of parent alienation is facing resistance from a number of groups. They say the concept is based off of faulty methods or pseudo-science. Why do you think they say so?